Pressure medium operable drive for giant antifriction bearings

ABSTRACT

THE INVENTION CONCERNS A FLUID DRIVE FOR EFFECTING RELATIVE ROTATION BETWEEN THE INNER AND OUTER RACES OF A GAINT ANTIFRICTION BEARING AND HAS RADIAL CYLINDERS CONNECTED TO THE OUTER RACE OF THE BEARING AND LOCATED INSIDE THE INNER RACE AND HAVING OUTWARDLY ACTING PISTONS THEREIN WHICH ENGAGE AN UNDULATING CAM CONNECTED TO THE INSIDE OF THE INNER RACE OF THE BEARING. A RING ELEMENT CONNECTED TO THE RADIALLY INNER ENDS OF THE CYLINDERS RECEIVES A TUBULAR BLOCK THAT IS CONNECTED TO THE INNER RACE AND FLUID IS SUPPLIED TO THE CYLINDERS AND EXHAUSTED THEREFROM BY PASSAGES EXTENDING FROM THE CYLINDERS THROUGH SAID MEMBER AND BLOCK.

United States Patent [54] PRESSURE MEDIUM OPERABLE DRIVE FOR GIANTANTlFRlCTlON BEARINGS 13 Claims, 5 Drawing Figs.

[52] US. Cl 91/498, 91/176, 91/180 [51] Int. Cl F011) 1/06,F01b13/06,F0ll33/02 [50] Field of Search t. 91/180,

205,176(Cursory); 103/161 (Cursory) Primary Examiner-Paul E. MaslouskyAttorneywalter Becker ABSTRACT: The invention concerns a fluid drive foreffecting relative rotation between the inner and outer races of a giantantifriction bearing and has radial cylinders connected to the outerrace of the bearing and located inside the inner race and havingoutwardly acting pistons therein which engage an undulating camconnected to the inside of the inner race of the bearing. A ring elementconnected to the radially inner ends of the cylinders receives a tubularblock that is connected to the inner race and fluid is supplied to thecylinders and exhausted therefrom by passages extending from thecylinders through said member and block.

PRESSURE MEDIUM OPERABLE DRIVE FOR GIANT ANTIFRICTION BEARINGS Thepresent invention relates to a pressure fluid operable drive for giantantifriction bearings, especially ball turntables, in which theantifriction bearings may be arranged in one or two rows. Such giantantifriction bearings comprise an outer ring and an inner ring of whichone ring is connected to the rotatable part of an implement, as forinstance an earth-working machine, whereas the other ring is connectedto the nonrotatable part of such implement. The pressure fluid operabledriving units comprise a cylinder and a piston and are arranged in thefree inner chamber of the ball turntable in a plane perpendicular to theaxis of rotation of the turntable while the space within the area of thetuning axis is free for mounting conveying elements, such as linkages,control conduits, etc.

To an ever increasing extent, normally such giant antifriction bearingsas they are used, for instance, with movable earth-working machines orcranes and stationary cranes or other implements in a pivotable orrotatable upper part thereof, are driven in such a way that the bearingring provided for the rotary movement has its circumference on theoutside or the inside provided with teeth which mesh with a pinion whichin its turn is driven by a motor through the intervention of a stepdowntransmission. Such drives require relatively considerable space andfurthermore have almost always to be mounted above or below the bearingring plane. Furthermore, the mechanical or similar brakes required forthe braking operations take up considerable space. This represents agreat disadvantage with respect to an expensive construction. Inaddition thereto, for carrying out the various working operations asthey are required, for instance, with earth-work ing machines, notmechanical power-conveying elements, such as chains, cables and thelike, are used, but pressure fluid operable devices. Since withimplements of this type already pressure fluid operable devices arepresent, it would appear expedient and advantageous to use such pressurefluid operable devices also for' the drive effecting the tilting ortuning movement of the 'upper, part without the interposition of amechanical drive.

Such designs according to which the driving units are mounted in theinterior of the ball turntable so that the central area of the turningaxis remains free for the passage of control conduits, rods, etc., areknown.

It is an object of the present invention to provide a pressure fluidoperable drive, especially for the about outlined purpose, which willassure'a constant uniform and even pivoting or turning movement of theupper part relative to the nonrotatable lower part and in additionthereto will also assure that no radial pressure from the turning orpivoting drive is to be absorbed by the bearing system, particularlysince ball turntable are involved which are to be used in connectionwith giant antifriction bearings or bearing systems for the transmissionof high torques.

It is a further object of this invention to provide an arrangement asset forth in the preceding paragraph in which the useful space in theupper part of the implement will not be taken up by heavy turning drivesand brakes.

It is still another object of the present invention to provide anarrangement as set forth above which with small implements will be ableto transmit torques of approximately 5,000 mic. and with largeimplements to transmit torques up to 100,000 mk.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawings, in which:

FIG. 1 illustrates a longitudinal section through a ball turntable witha pressure fluid operable drive, said section being taken along the linel-[ of FIG. 2.

FIG. 2 is a section taken along the line H of FIG. 1.

FIG. 3 shows by way of a cutout an inner ring with a double cam surface.

FIG. 4 shows by way of a cutout an inner ring with a single cam surface.

FIG. 5 illustrates the arrangement of a braking element by way ofalongitudinal section taken along the line V-V of FIG. 2.

The pressure fluid operable drive according to the present invention ischaracterized primarily 'in that the cylinders are detachably arrangeddirectly on the outer ring and on a counter ring which is connected tothe outer ring and provided with open annular passages and bores whilethe pistons subjected to the pressure fluid cooperate through theintervention of rollers with a closed sine-shaped cam surface providedon the inner side of the inner ring.

The rollers are spherically by means of transverse bolts connected tothose ends of the pistons which face the circumference of the ballturntable in order to adapt themselves to the mutual inclined positionsof the bearing rings with regard to the bearing plane as brought aboutby the torque loads, and also to adapt themselves to the lack ofuniformity of the cam surfaces when two cam rings are employed.

The number of the driving units amounts to a=(42n) with n=1 or a wholemultiple of I. The number will be increased when the torque to betransmitted is, for instance, relatively high. In view of this increasein number, the cam path is sub-. jected to less stresses when theindividual pistons which are acted upon by the pressure medium restagainst the cam path or surface. The cam surface or path itself may behardened, tempered or may be naturally hard.

When employing a greater number of driving units, the radial pressureacting upon the bearing system through the turning or pivoting operationwill be equalized inasmuch as two driving units diametrically oppositelyarranged with regard to each other are connected to the counter ring.The cam path is so designed that each inner reversing point has locatedopposite thereto an outer reversing point. The cam path is furthermoreso designed that the total of the two individual piston strokes measuredfrom the inner dead center point and pertaining to two oppositelylocated pistons equals the total stroke of one piston. For thecooperation of piston and cam path there is provided at least oneroller. When employing two rollers, such rollers are guided by two campaths having the cylinders arranged therebetween.

According to a further feature of the invention, for influencing theconveying of the pressure fluid, there is provided a control ring whichdoes not rotate but is resting on a pan carrying the inner ring. Thiscontrol ring establishes connection between the annular passages and thebores of the counter ring which lead to the cylinder. The bores in thecounter ring lead to a common opening on the side of the cylinderconnec-' tion and on the other side of the counter ring cooperate withconnecting bores of the control ring which are located in differentplanes and lead to the annular passages of the counter ring.

Independently of obtaining the braking of an initiated pivoting orturning, movement by controlling the supply of pressure fluid to thepiston, there is provided a further pressure fluid controlled andmechanically effective braking device. More specifically, on the outerring between the driving units, i.e. between the cylinders, there arearranged braking elements which in axial direction are adapted to besubjected to pressure fluid and act upon the pan whichreceives the innerring. Each individual braking element comprises a guided hollow cylinderwhich carries a plate provided with a brake lining. The control of thisbraking device is effected by a separate control conduit. This brakingdevice is not necessary under all circumstances since also a brakingoperation can be realized by the control valve for obtaining a left-handor right-hand turning movement.

Referring now to the drawing in detail, a ball turntable 10 is showntherein as it may be used, for instance, in a movable earth-workingmachine as connecting element between the undercarriage and thepivotable or rotatable upper carriage. The ball turntable I0 comprisesan inner ring 11 and an outer ring 12 which latter may be composed, forinstance, of the two outer ring sections 121 and 122. The pressureforces are in the specific instance shown in the drawing transferred byone row of balls 13. The inner ring 11 rests on a pan 14 to which it isconnected by screws and which is adapted to be connected with anonrotatable lower part, as for instance an undercarriage.

According to FIG. 1, the inner ring 11 has connected thereto an upperring 151 the inner circumference of which is provided with a sine-shapedpath 15, and has furthermore connected thereto a correspondinglydesigned lower ring 152.

According to FIG. 3, the inner ring 11 is so designed that itsimultaneously comprises the curved path 15 and, more specifically, intwo different planes, whereas FIG. 4 shows the inner ring 14 with onlyone curved path 15.

Threadedly connected to the outer ring section 121 are cylinders 16which pertain to the driving units and extend perpendicularly withregard to the axis of rotation of the turntable while being locatedin'thefree inner chamber of the turntable 10. The flanges 161 of thecylinders 16 are fitted to a counter ring 17. A piston 18 which isadapted on one side to be sub jected to a pressure fluid medium foractuation of the piston is guided within the interior of the cylinder 16and has one of its ends provided with a roller 19 (FIG. 4) whichcooperates with the curved path or cam 15. In conformity with the designhaving two curved paths or cam surfaces 15, as shown in FIGS. 1 and 3,two rollers 19 are provided. The rollers 19 are supported by transversebolts which are guided in spherical recesses of the pistons 18. Ifdesired, the bore of the roller 19 may be spherical (FIG. 4). Thecounter ring 17 which is connected to the outer ring section 121 takespart in the pivoting or turning movement of the outer ring 12. Theannular passages 171, 172 which are provided in the counter ring 17 areadapted through bores 1711, 1712 and a simple reversing valve to beconnected'to a pump (not illustrated). The bores 173, 174 which leadinto a common opening 171 located on the side of the fitted flange 161cooperate on the other side of the counter ring 17 with connecting bores201, 202 which are located in different planes and pertain to anonrotatable control ring 20. These connecting bores 201, 202 representthe connection with the annular passages 171, 172.

When subjecting the piston 18 to pressure fluid while the pressuremedium from the annular passage 172 acts through connecting bore 202,bore 173 and opening 175 upon the piston surface of the piston 18, thepiston 18 with its roller 19 is pressed outwardly against the camsurface 15 asa result of which the rotating or pivoting movement isinitiated. The diametrically oppositely located piston 18 is returned toits inner dead center point by the cam surface 15 because the medium ispressureless and flows back through opening 175, bore 174 and connectingbore 201 into the annular passage 171 and through the connection 1711 tothe pump. The com necting bore 201 of one plane is offset with regard tothe connecting bore 202 of the other plane on the outer circumference ofthe control ring 20 in such a way that the opening 175 moves in front ofthe connecting bore until the bore 19 of the piston 18 moves over thepertaining cam path or cam surface 15. If it is desired that the upperpart moves in opposite direction, in the control unit (not shown) theother pressure fluid conveying conduit leading to the control ring 20 issubjccted to pressure so that the previous pressure fluid conveyingconduit which is now without pressure will act as return conduit for thepressure fluid from the cylinder 16.

For stopping the outer'and inner ring 12, 11 with regard to each otherso that any rotary movements are prevented, the valves (not shown) ofthe two feeding conduits are closed in the control unit. For braking theturning movement, a counter control is effected to a greater or lesserextent by means of the control valve which means that the control valveis shifted over for the opposite rotary movement.

In order during the braking and blocking operations to prevent thepressure in the conduits from increasing too much, a pressure reliefvalve is provided in the conduits, and this pressure relief valve is soadjusted that its opening pressure is slightly above the workingpressure for producing the maximum torque but is below the permissibleworking pressure.

For freewheeling after initiating or carrying out a rotary movementtoward the right or toward the left, the control valve is so adjustedthat no pressure is conveyed by the pump to the pistons 18. The pistons18 which are returned to their inner dead center points by means of thecam path 15, release their pressure medium through simultaneouslyopening return valves which precede the control valve for the pressurefluid drive. For blocking the rotary movement, any delivery orwithdrawal of any pressure medium is interrupted or prevented in thecontrol valve while for a possible emergency relief valves are providedin the two conduits between pres sure cylinders and control valve whichrelieve too high a pressure ofthe pressure medium.

independently of the above-mentioned braking operation, there may beprovided a braking device which is adapted to be controlledindependently but likewise by means of the pressure medium.

On the inner side of the outer ring section 121, between the individualcylinders 16, these braking units are provided which comprise a guidedhollow cylinder 21 supporting a plate 23 provided with a brake lining22. When the hollow cylinder 21 is subjected to the influence of apressure fluid, the brake lining 22 will rest on the inside of the pan14. A pressure spring 24 which is arranged in the hollow cylinder 21 andwhich, when the hollow cylinder 21 moves outwardly, rests against apushrod 25 will, when the braking conduit 26 becomes pressureless,return the cylinder 21 so that the brake is released again.

It is, of course, to be understood that the present invention is, by nomeans, limited to the particular construction shown in the drawing butalso comprises any modifications within the scope of the appendedclaims.

We claim:

1. A drive arrangement for a giant antifriction bearing which has outerand inner races and antifriction elements interposed between the races,one of said races being adapted to be connected to a nonrotatablemachine part and the other to a rotatable machine part, and drive meansinside said inner race for driving said races and, therefore, said partsin relative rotation, said drive means comprising: a tubular member atthe center of said bearing coaxial therewith and connected to said outerrace, radial cylinders uniformly circumferentially distributed insidesaid inner race and having their radially inner ends connected to saidtubular member, pistons in said cylinders reciprocable therein towardand away from said inner race, undulating cam means connected to theinside of said inner race and engaged by said pistons, and means forsupplying pressure fluid through said tubular member to the radiallyinner ends of said cylinders and for exhausting fluid from saidcylinders through said tubular member, said tubular member having aflange at one end whereby the interior of said tubular member has aperipheral wall and an end wall, a pair of annular grooves in said endwall adapted for being connected to a source of pressure fluid and toexhaust respectively, an annular block connected to said inner race andfitted in said tubular member so as slidably to engage said end wall andperipheral wall thereof, first and second passages in said block leadingfrom respective ones of said grooves to the periphery of said block, andpassage means in said tubular member leading from said cylinders intosaid cavity and communicating alternately with said first and secondpassages as said races rotate relatively and cause relative rotation ofsaid tubular member and block.

2. A drive arrangement according to claim 1, in which the number of saidcylinders is equal to an even number greater than 4 and the number ofundulations on said cam means differs from the number of cylinders byone.

3. A drive arrangement according to claim 2, in which the saidundulations of said cam means are so shaped that the distance betweenany point along the cam and the point on the cam diametrally oppositeremains constant.

4. A drive arrangement according to claim 1, in which said pistons haveroller means thereon engaging said cam means.

5. A drive arrangement according to claim 4, in which said cam means isin the form of a pair of parallel axially spaced cams.

6. A drive arrangement according to claim 4, in which said roller meansare tiltably carried on said pistons.

7. A drive arrangement according to claim 1, in which said first andsecond passages have their ends at the periphery of said block arrangedin respectively different axial planes and spaced circumferentiallyabout said block so as to communicate alternately with the said passagemeans in said tubular member in succession, the angular spacing betweensuccessive ones of the ends of each of said first and second passagesbeing equal to the angular spacing between adjacent ones of theconvolutions on said cam means.

8. A drive arrangement according to claim 1, which includesfluid-operable brake means disposed between at least one adjacent pairof said cylinders operatively carried by one of said races andexpan'sible by fluid pressure into operative braking engagement with theother of said races.

9. A drive arrangement according to claim 8, in which said brake meanscomprises piston-cylinder means. friction element means on the end ofthe piston means for operative braking engagement with said other ofsaid races upon axial expansion of said piston-cylinder means, and meansbiasing said piston-cylinder means toward collapsed position.

10. A driving arrangement according to claim 7, which includes a firstplatelike element on one axial side of said bearing connecting saidouter race with said member and a second platelike element on the otheraxial side of said bearing connecting said inner race with said annularblock and having a central hole therein, said radial cylinders andpistons and cam means all being contained in the axial space betweensaid platelike elements.

11. A driving arrangement according to claim 10, in which points alongsaid cylinders remote from said tubular member are connected to saidfirst platelike member to support said cylinders in their respectiveradial positions.

12. A driving arrangement according to claim 10, in which said secondplatelike element engages said block on the end of the block oppositesaid end wall of said tubular member and confines said block in saidtubular member, said second platelike element having a central axialflange telescopically and nonrotatably engaging the inside of saidannular block and a peripheral axial flange loosely telescoping oversaid outer race so as to be freely rotatable relative thereto.

13. A driving arrangement according to claim 10, which includes aplurality of axial cylinder means carried on the side of said firstplatelike element which faces said second platelike element andpositioned between adjacent pairs of said radial cylinders, a pistonmember in each said cylinder means spring urged toward retractedposition therein and having friction means on the outer end thereof, andmeans for supplying fluid under pressure to said cylinder means toactuate said piston elements to press said friction means into brakingengagement with said second platelike element.

